For example, in a multi-pole connector mounted to a printed wiring board and connecting printed wiring boards so that they are superimposed, it is desired that the connector is shortened (a height reduction) in a fitting direction due to a reduction in size of equipment for housing a circuit.
In order to reduce the height of the connector, it is necessary to shorten each contact (conductive terminal) in a fitting direction. The contacts require an elastic force for being press-fitted to each other in order to secure a conductive contact, and a fitting length to some extent so that the contacts are not easily separated.
As described in Patent Documents 1 and 2, in a case where contacts are formed by bending a metal plate, a radius dimension for bending is required, so that there is a limitation in reducing the height in order to secure the fitting length. Further, in a case where contacts are formed by subjecting a metal plate having a certain plate thickness to bending work, an elastic force is controlled by the plate thickness. As a method for adjusting the elastic force of the metal plate, there is a method in which a metal plate is subjected to press working (crushing, beating) to partially change the thickness. However, residual stresses or lattice defects occur due to the press working, so that the connector has a shorter lifetime, and variations in thickness become large on a product-to-product basis.
Patent Document 3 discloses a connector in which pins and sockets that are erected in a normal line direction of substrates are formed by a plating technique. The sockets of Patent Document 3 are each elastically deformed so as to fall on the substrate when receiving the pins. For increasing a deformation amount of each pin, it is necessary to increase a height of the socket so that an elastically deformed region is increased. Therefore, as in the connectors of Patent Documents 1 and 2, if the pins and the sockets are provided with an overlap in a fitting direction to improve a retention force, or a click feeling that a user feels attachment and detachment is imparted, a length of the connector becomes longer in the fitting direction.
In addition, since the contacts used for such small-type connectors are extremely small, forming them by machining is not realistic.    Patent Document 1: Japanese Laid-Open Patent Application No. 2004-55436    Patent Document 2: Japanese Patent Laid-Open Application No. 2006-66349    Patent Document 3: Japanese Patent No. 3774968